Compressive and Non-compressive Acceleration of Suprathermal Particles in the Heliosphere

Abstract:

We discuss compressive and non-compressive acceleration of charged particles in terms of the proper transport equations cast into a Lagrangian frame. We present numerical simulations for particle acceleration due to random compression of the plasma and also present a simple model to include the back-reaction of accelerated particle population on the background plasma. We also discuss particle acceleration due to the random variation of the magnetic field strength which may occur without net density compression. Here we use the focused transport equation cast into Lagrangian form. Model simulation will be presented and the momentum diffusion coefficient is related to the spectrum of magnetic fluctuations.